"It is now clear that there are going to be massive flooding disasters around the globe," David Vaughan of the British Antarctic Survey told the Guardian. "Populations are shifting to the coast, which means that more and more people are going to be threatened by sea-level rises."

Not only are ice sheets in Greenland and Antarctica breaking up faster than scientists expected, but more of their melt water is flowing into oceans, he said, which will raise sea levels by 3.3 feet (1 meter) by 2100. The IPCC previously estimated that sea levels would rise by 7.9 to 23.6 inches (20 to 60 centimeters) by then.